Integrated wheel end coupler

ABSTRACT

An integrated wheel end coupler for replacing an OEM coupler is disclosed. Since the current device is a replacement part for the OEM actuator, it has the same overall external dimensions and mounts in the vehicle in the same manner as a replacement OEM actuator. The coupler has a ring gear with splines dimensioned to mesh with splines on the half-shaft and hub. Preferably, the ring gear includes an internal insert positioned between the half-shaft and hub that prevents slippage off of the splines. The ring gear is located so that the splines on both the hub and the half shaft are locked together mechanically and they spin at the same rate of speed. The coupler also includes pins to receive and close off the airlines associated with the OEM actuator being replaced, and a   —grease fitting that allows the application of grease to the coupled parts.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application 62/033,504, filed Aug. 5, 2014, which is incorporated by reference as if fully set forth.

FIELD OF INVENTION

The present invention relates generally to an actuator for connecting a front wheel drive shaft to the front wheel hub. In particular, the present invention relates to an actuator that connects the front wheel drive shaft to the front wheel hub in a fixed connection without requiring any replacement of the original equipment manufacturer's parts (OEM) known as an integrated wheel end actuator (actuator).

BACKGROUND

The present invention addresses a problem with an OEM actuator for connecting the front wheel drive shaft to the front wheel hub. The OEM device is movable between engaged and disengaged positions through applying and removing air pressure. The OEM device is biased in toward the disengaged position.

The OEM actuator the invention replaces is mounted on the back of the steering knuckle to provide a ring gear that will couple the hub and a half shaft. The half shaft is inserted into the actuator, where its splines are fully engaged with the ring gear until it becomes activated and engaged with the splines of the hub. The OEM actuator is vacuum controlled. To engage 4WD, the vacuum is released and a spring moves the ring gear to a position where it engages both the half shaft and the hub. Before the released vacuum goes into the atmosphere, it is piped into the engine bay to avoid introducing contaminants to the upstream vacuum system.

The OEM actuator is prone to failure of the vacuum diaphragm and results in unexpected, erratic, or no 4WD engagement. Experience with the prior device has revealed a tendency for the OEM actuator to engage at inopportune times. Accordingly, it is desired to have a coupler that replaces the OEM actuator and eliminates the known failure points.

SUMMARY

The disclosed coupler includes a ring gear that engages or connects the front wheel drive shaft to the front wheel hub and eliminates the need for applying air pressure to the part. In addition, the actuator includes a grease fitting that permits the application of grease to the connection point.

When the splines on both the hub and the half shaft are mechanically locked together, they spin at the same rate of speed. When the vehicle is operating in 2WD the front wheel and the half shaft on one side of the vehicle are connected by the coupler and allowed to travel at a rate of speed that can be different from the other side of the vehicle. When the vehicle transfer case and front differential are shifted into 4WD, the corresponding front wheels and half shafts travel at the same rate of speed and allow the vehicles power to be diverted as needed without causing any internal damage to the 4WD system.

Because the current coupler does not need a moving ring gear, a plastic or nylon ring gear carrier holds the ring gear at the appropriate engagement height to ensure the ring gear meshes with both splined components. An additional advance of this design is the ability to provide a ring gear that is approximately twice the thickness or height of the one in the OEM actuator. This wider ring gear provides space for an internal groove that receives an internal snap ring that ensures the gear cannot disengage from either of the two splined components. There is a grease passage through the coupler housing that allows grease of be applied to the ring gear, splined shafts, and wheel hub bearing through a grease fitting mounted on the housing. Because the need for vacuum is eliminated, there are two solid pins that cap off the OEM vacuum lines

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a perspective view of the coupler;

FIG. 2 is a section view of the coupler; and

FIG. 3 is an exploded view of the coupler.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIG. 1, it can be seen that the assembled coupler (10) includes pins (7) and (8) in projection (11) that serve to block the airlines associated with an OEM device that was movable between engaged and disengaged positions through applying and removing air pressure. The pins 7 and 8 are solid because their purpose is to block or close off the vacuum lines associated with the OEM device.

FIG. 2 is a section view through the device of FIG. 1. As can be seen in FIG. 2, the ring gear (3), ring gear carrier (4) and the housing (5) are fixed relative to each other. When assembled in a vehicle, the assemble (10) is fixed in the engaged position with both a half-shaft and an associated hub so that they are linked mechanically and spin at the same speed.

With reference to FIG. 3, the individual components of the assembly (10) are shown in an exploded view. Since the current device is a replacement part for the OEM actuator, it has the same overall external dimensions and mounts in the vehicle in the same manner as a replacement OEM actuator. Likewise, the ring gear splines are dimensioned to mesh with the half-shaft and hub splines. However, there are some differences. The solid pins (7) and (8) in the project (11) are located to receive and close off the airlines associated with the OEM actuator being replaced. The grease fitting (9) and the project (12) are new components in the present solution and add the feature that allows the application of grease to the coupled parts.

As noted previously, the external dimensions of the coupler mimic the OEM actuator even though the need for a mechanism, vacuum in the OEM part, to engage, disengage and bias the ring gear is eliminated. Due to this simplification, the housing (5) can accommodate a ring gear (3) that is approximately twice the thickness or height of the OEM ring gear, see FIG. 2. This larger ring gear has a groove (3′) that accepts the snap ring (2), which serves as a mechanical safety lock that prevents the ring gear (3) from deviating away from the engagement zone mating the half-shaft and hub within the coupler (10). This maintains the mechanical link between the half-shaft and hub and avoids slippage between them. 

What is claimed is:
 1. A coupler for connecting a constant velocity axle and a wheel hub in an engaged condition, the coupler comprising: a housing that has a predetermined outer configuration that mates with a predetermined location on a steering knuckle, and an interior channel that is configured to receive a ring gear carrier; a ring gear carrier that fits within the housing and positions a ring gear in a predetermined location for mating with a constant velocity axle and wheel hub; and, a ring gear that mounts in the ring gear housing and has splines dimensioned to mate with splines on a constant velocity axle and with splines a wheel hub.
 2. The coupler of claim 1 wherein the ring gear splines are internal splines.
 3. The coupler of claim 1 wherein the ring gear has a circumferential groove and the ring gear carrier has a circumferential projection that is received within the circumferential groove.
 4. The coupler of claim 1 wherein the housing and ring gear carrier define an internal lubrication channel.
 5. The coupler of claim 1 wherein the ring gear has an internal groove dimensioned to receive a snap ring that separates the splines on the ring gear.
 6. A coupler for connecting a half-shaft and a wheel hub of a vehicle drive train in an engaged condition, the coupler comprising: a housing that has an interior channel that is configured to receive a ring gear carrier; a ring gear that is mounted in the ring gear housing, has internal splines dimensioned to mate with splines on a haft-shaft and a wheel hub, and has an internal groove that interrupts the internal splines; and, an insert in the internal groove that separated the half-shaft and the wheel hub.
 7. The coupler of claim 6 further comprising a ring gear carrier positioned within the housing.
 8. The coupler of claim 7 wherein the housing and ring gear carrier define an internal lubrication channel.
 9. The coupler of claim 6 wherein the insert in the internal groove that separated the half-shaft and the wheel hub is a snap ring. 